I got to work on a guy's Surface tablet a couple days ago. While it was nice and very fast, every time I had to do something on the desktop, it was like trying to read the fine print on a TV commercial.
Since Win8, Windows has DPI scaling on the desktop that actually works (actually it was mostly working in Win7 already, but 8 and 8.1 polished it further).
Surface, in particular, scales everything to 150% by default, if I remember correctly. The text on mine is about the same size as on the desktop. Of course, this means that not quite as many things fit, so some people manually change the setting back to 100%, making everything tiny, but fitting more onto the screen. That guy whom you know must have done that.